A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyrights whatsoever.
In general, the invention relates to controlled vehicle systems. More specifically, the invention relates to steering angle information utilized within varying vehicle systems and, in particular, to a method for providing initialization and the accurate angle sensing of steering direction (also known in the art as steering angle, steering wheel angle, and steering hand wheel angle).
Modern automotive technologies utilize advanced system algorithms to provide for advanced vehicle safety, comfort, control, and additional like attributes. These algorithms rely upon driver response, driver preferences, vehicle sensor output, hardcoded constants, and determined variables as input for processing the preferred function. An algorithm""s result is then relayed for utilization within the pertinent system. Many of these algorithms rely upon the values defined by each other as inputs to be processed for additional controls. One value often required by alternate algorithms is for a vehicle""s precise steering wheel center or steering wheel angle off center.
Prior art xe2x80x98steering angle determinationxe2x80x99 algorithm""s provide accurate results, but at a cost. One such cost involves the quality of a xe2x80x98steering angle determinationxe2x80x99 algorithms result. Current xe2x80x98steering angle determinationxe2x80x99 algorithms rely upon dedicated steering sensors. If more than one algorithm needs a raw steering wheel angle value, multiple sensors must be added thus increasing manufacturing costs.
Additionally, current xe2x80x98steering angle determinationxe2x80x99 algorithms require three or more driver or sensor inputs such as yaw rate and lateral acceleration in addition to the steering sensor, in order to accurately determine a steering angle. Statistically, the larger the number of required input""s, the higher the probability of inaccurate results caused by faulty driver input or malfunctioning sensors. Additionally, the larger the number of vehicle sensors, the higher the vehicle costs of manufacturing.
In addition, current xe2x80x98steering angle determinationxe2x80x99 algorithms can hamper the proficiency of additional vehicle algorithms. This can be caused by the amount of time required for the steering sensor and additional sensors to provide sufficient data for the xe2x80x98steering angle determinationxe2x80x99 algorithm to accurately determine the angle of a steering wheel from center.
Therefore, it would be desirable to have an algorithm that quickly determines absolute steering wheel angle information, that requires a minimum number of inputs, and that further improves upon the above-mentioned situations and prior art.
One embodiment of the invention provides a method of determining a vehicle steering wheel angle. At least one steering sensor output and a vehicle speed signal are received. A centered steering angle is determined based on the received vehicle speed signal and the steering sensor output.
Another embodiment of the invention provides a system for determining a vehicle steering angle including a means for receiving at least one steering sensor output, a means for receiving a vehicle speed signal, and a means for determining a centered steering angle based on the received vehicle speed signal and the steering sensor output.
Another embodiment of the invention provides a computer readable medium storing a computer program comprising computer readable code for receiving at least one steering sensor output. The computer program further comprises computer readable code for receiving a vehicle speed signal and for determining a centered steering angle based on the received vehicle speed signal and the steering sensor output.
The foregoing and other features and advantages of the invention will become further apparent from the following detailed description of the presently preferred embodiment, read in conjunction with the accompanying drawings. The detailed description and drawings are merely illustrative of the invention rather than limiting, the scope of the invention being defined by the appended claims and equivalents thereof.